1. FIELD OF THE INVENTION
The invention relates to blind rivet setting tools and, in particular, an automatic system for providing a liquid to the rivet setting mechanism of the tool. The liquid serves to lubricate, clean, and cool the rivet setting mechanism.
2. DESCRIPTION OF THE PRIOR ART
The carbon steel wire used for rivet mandrels is typically coated with phosphate to prevent rusting. Such phosphates, however, present problems in the mandrel heading operation by causing deposits and gumming up the heading dies and cutters. It is known that phosphate build-up problems are addressed in the heading operation by providing oil on the wire in a continuous dripping manner.
Finished carbon steel mandrels also are phosphate coated and present similar gumming problems with respect to the serrated jaws of typical rivet setting mechanisms. Such jaws may become plugged or fouled from phosphate build-up. It is also known that phosphate build-up problems on serrated holding jaws of an apparatus for testing the endurance of rivet setting tools were addressed by providing an uninterrupted flow of a lubricant oil to the holding jaws.
The rivet setting mechanism of a rivet setting tool encounters more contamination than the phosphate build-up described above in connection with holding jaws. As the rivet mandrel is broken within the housing of the rivet setting mechanism, small metallic particle debris is formed which adds to contamination. Such metallic particles may deposit on various parts of the mechanism and cause high rates of wear.
Blind rivet setting tools are typically lubricated and cleaned by inserting the nosepiece and housing of the tool, in which the rivet setting mechanism and jaws are located, into a container of lubricant and repeatedly actuating the mechanism. The excess is allowed to drip back into the container and residues are wiped off. Drawbacks with this approach include the fact that it is extremely time consuming and messy. Also, each tool operator will perform the task differently and at different intervals. Thus, with this approach, there is no way to insure that the mechanism and jaws are properly lubricated, either in a timely manner or with an appropriate quantity of lubricant. In addition, this approach has little utility in connection with automatic or robotic rivet installation systems, which would have to be taken out of service to lubricate in this manner.